CONTEXT: The effect of local cooling on muscle strength presents conflicting debates, with literature undecided as to the potential implications for injury, when returning to play following cryotherapy application. OBJECTIVE: To investigate concentric muscle strength following local cooling over the anterior thigh compared with the knee joint in males and females and the temporal pattern over a 30-minute rewarming period. DESIGN: Repeated-measures crossover design. METHOD: Twelve healthy participants randomly assigned to receivecooling intervention on one location, directly over either the anterior thigh or the knee, returning 1 week later to receive the cooling intervention on opposite location. Muscle strength measured via an isokinetic dynamometer at multiple time points (immediately post, 10-, 20-, and 30-min post) coincided with measurement of skin surface temperature (Tsk) using a noninvasive infrared camera. RESULTS: Significant main effects for time (P ≤ .001, η2 = .126) with preice application higher than all other time points (P ≤ .05) were demonstrated for both peak torque and average torque. There were also significant main effects for isokinetic testing speed, sex of the participant, and position of the ice application for both peak torque and average torque (P ≤ .05). Statistically significant decreases in Tsk were reported in both gender groups across all time points compared with preintervention Tsk for the anterior thigh and knee (P < .05). CONCLUSIONS: Reductions reported for concentric peak torque and average torque knee-extensor strength in males and females did not fully recover to baseline measures at 30-minute postcryotherapy interventions. Sports medicine practitioners should consider strength deficits of the quadriceps after wetted ice applications, regardless of cooling location (joint/muscle) or gender.
RCT Entities:
CONTEXT: The effect of local cooling on muscle strength presents conflicting debates, with literature undecided as to the potential implications for injury, when returning to play following cryotherapy application. OBJECTIVE: To investigate concentric muscle strength following local cooling over the anterior thigh compared with the knee joint in males and females and the temporal pattern over a 30-minute rewarming period. DESIGN: Repeated-measures crossover design. METHOD: Twelve healthy participants randomly assigned to receive cooling intervention on one location, directly over either the anterior thigh or the knee, returning 1 week later to receive the cooling intervention on opposite location. Muscle strength measured via an isokinetic dynamometer at multiple time points (immediately post, 10-, 20-, and 30-min post) coincided with measurement of skin surface temperature (Tsk) using a noninvasive infrared camera. RESULTS: Significant main effects for time (P ≤ .001, η2 = .126) with preice application higher than all other time points (P ≤ .05) were demonstrated for both peak torque and average torque. There were also significant main effects for isokinetic testing speed, sex of the participant, and position of the ice application for both peak torque and average torque (P ≤ .05). Statistically significant decreases in Tsk were reported in both gender groups across all time points compared with preintervention Tsk for the anterior thigh and knee (P < .05). CONCLUSIONS: Reductions reported for concentric peak torque and average torque knee-extensor strength in males and females did not fully recover to baseline measures at 30-minute postcryotherapy interventions. Sports medicine practitioners should consider strength deficits of the quadriceps after wetted ice applications, regardless of cooling location (joint/muscle) or gender.